Rotary pump



C- E. BAILEY Feb. 28, 1967 ROTARY PUMP Filed Aug. 5, 1965 FIG. 2

INVENTOR Y C E.BAIL.EY

A 7' TOR/VEVS United States Fatent )fifice Patented F eb. 28, 1967 3,306,227 ROTARY PUMP Clyde E. Bailey, Beatrice, Nehru, assignor to Phillips Petroleum Company, a corporation of Delaware Filed Aug. 5, 1965, Ser. No. 477,413 6 Claims. (Cl. 103-126) This invention relates to rotary pumps. In one aspect this invention relates to a rotary pump provided with a liner or liners in the pumping cavity thereof. In another aspect this invention relates to a method for installing a liner or liners in the pumping cavity of a rotary pump.

Rotary pumps are widely employed for pumping a great variety of fluids, both liquid and gases. Such pumps are particularly useful for pumping heavy liquids such as heavy oils, molten asphalt, etc. In a rotary pump, such as a gear pump wherein a pair of rotors or gear means rotate in a pair of gear chambers, for good pumping efiiciency a running engagement, or at least a very close clearance, is required between the inner peripheral wall of said chambers and the peripheral tips or edges of the rotary gear means. During use said peripheral tips or edges of the gear means and/ or the wall of said chambers (more usually the chamber wall) becomes worn, resulting in a loss of pumping efiiciency. When this happens a new pump case, or a liner for the pump case, is required.

Various types of liners and methods for installing same have been provided in the prior art. One of the problems associated with employing liners in such rotary pumps is securing the liner in place in the gear chamber or pumping cavity. In some instances, the liner is bonded to the chamber wall. This is usually an inconvenient and expensive method which requires the liner to be fabricated within close tolerances so as to provide a good bonding surface. Furthermore, the bonding sometimes loosens and the liner will shift into the path of the rotating gears or other rotary means. In other instances, the liner is fabricated so as to provide a close press fit. This is also undesirable because it requires that the liner be fabricated with even closer tolerances and further increases the cost of the liner. Frequently, the installation of liners is further complicated by the shape of the pump case and the location of the inlet and outlet ports therein relative to the pumping cavity.

The present invention solves the above problems by providing a simplified, easily fabricated liner and a method for installing-said liner. Broadly speaking, the present invention resides in a liner having a shape complementary to and mounted on the wall of the gear or rotor chamber with the ends of said liner extending slightly beyond the adjacent respective ends of said chamber and into recesses provided in the pump housing end plates which close opposite ends of said chambers. The extended ends of said liners, being positioned in said recesses, effectively retain the liner in place both longitudinally and circumferentially.

An object of this invention is to increase the life of a rotary pump, e.g., a gear pump. Another object of this invention is to provide a simplified and effective liner for the pump body or housing of a rotary pump, e.g., a gear pump. Another object of this invention is to provide a method for lining the rotor chamber or chambers of a rotary pump, e.g., a gear pump. Still another object of this invention is to provide a method for increasing the life of a rotary pump, e.g., a gear pump. Other aspects, objects, and advantages of the invention will be apparent to those skilled in the art in view of this disclosure.

Thus, according to the invention, there is provided a pump comprising: a housing having an inlet port and an outlet port; a chamber formed in said housing and comprising a pumping cavity communicating with said inlet of said second liner extends slightly beyond the adjacent port and said outlet port; a liner of complementary shape mounted on the wall of said chamber, each end of said liner extending slightly beyond the respective ends of said chamber wall; a first and a second end plate, each substantially closing one end of said housing; and a recess of a shape like that of said liner formed in the inner wall of each of said plates for receiving said extended ends of said liner when said end plates are mounted on said housing.

Further according to the invention, there is provided a method for overhauling and installing a liner in a gear pump comprising a first gear chamber formed in said housing, a second gear chamber formed in said housing in center point alignment with and spaced apart from said first chamber, said two chambers and the space therebetween defining a pumping cavity, and first and second end plates for mounting on opposite ends of said housing to substantially close said pumping cavity, said method comprising: reboring each of said chambers to a larger diameter; pressing into each said rebored chamber a liner having a shape complementary to the wall thereof, the ends of each of said liners extending slightly beyond the adjacent respective ends of said chambers; forming first and second recesses in each of said end plates, said recesses having a shape like that of and being positioned for receiving said extended ends of said liners when said end plates are mounted on opposite ends of said housing; and mounting said end plates on opposite ends of said housing with said ends of said liners extending into said recesses.

It will be particularly noted that the extended ends of the liner elements are extended into the complementary recesses provided in the end plates. This cooperation between said extended ends and said recesses provides one of the outstanding advantages of the invention in that the liner elements are firmly held in place without the necessity of bonding agents or close press fits between said liners and the wall of the gear chamber.

FIGURE 1 is a view in elevation, partly in cross-see tion, of a gear pump illustrating a liner installed in a gear chamber of said pump in accordance with the invention.

FIGURE 2 is a perspective view of a liner in accordance with the invention.

FIGURE 3 is a perspective view of the pump body or housing of the gear pump of FIGURE 1, illustrating liners installed in the upper and lower gear chambers in accordance with the invention.

FIGURE 4 is a perspective view of an end plate of the pump of FIGURE 1 showing the recesses of like shape formed in the inner face of said end plate which cooperatively engage the extended ends of the liners illustrated in FIGURE 3.

Referring now to the drawings, wherein like reference numerals are employed to denote like elements, the in vention will be more fully explained. In FIGURES 1 3, and 4, the gear pump illustrated comprises a pump body or housing 10 having an inlet port 12, and an outlet port 14 (in FIGURE 3 the internal end of said outlet port 14 is shown). Disposed and formed within said housing 10 are first and second substantially circular spaced apart and aligned chambers 16 and 18. Said chambers are aligned with their center points in the same plane. Said chambers, together with the space 20 therebetween, form a pumping cavity which communicates with said inlet port 12 and said outlet port 14. A first arcuate liner 22 having a shape complementary to the wall of said cham- :ber 16 is mounted in said chamber contiguous with the wall thereof with each end of said liner extending slightly beyond the adjacent respective end of said wall. A second arcuate liner 24 is mounted in said second chamber 18 contiguous with the wall thereof, and again each end respective end of said wall. Said liners can be fabricated J from any suitable wear-resisting material, e.g., a hard metal. A first end plate 26 and a second end plate 28 are mounted on and substantially close opposite ends of said housing 10.

Referring now to FIGURE 4, there are shown first and second arcuate recesses 30 and 32 which are formed in the surface of each of said end plates 26 and 28 which faces said pumping cavity. Said recesses 30 and 32 each have the same radius of curvature of said first liner 22 and said second liner 24, respectively. Said recesses 30 and 32 are positioned in the inner surface of said end plates so as to receive the extended ends of said liners 22 and 24, respectively, when said end plates are mounted on said housing.

Referring again to FIGURE 1, the remainder of said pump comprises a pair of bearing housings 34 and 36. Said bearing housings may be formed integrally with said end plates 26 and 28, as shown, or they may be formed separately. Closure plates 38 and 40 are provided for closing the outer ends of said bearing housings 34 and 36, respectively. Extending outwardly from said closure plate 40 is a packing gland assembly 42 which is usually formed integrally with said closure plate 40. Shaft 44 extends through said packing gland assembly, through a set of bearings disposed in bearing housing 36, and is connected to a gear or rotor 46 which is here illustrated as being provided with helical teeth on the surface thereof. It will be understood to be within the scope of the invention to employ rotor members having other types of gear teeth thereon. A stub shaft (not shown), suitably mounted in bearings disposed in bearing housing 34, is attached to the other end of said rotor or gear 46. As will be understood by those skilled in the art, there is also provided in said housing a second rotor or gear (not shown) which is disposed below rotor or gear 46 and meshes therewith. Said second rotor or gear is suitably mounted on stub shafts which are in turn suitably journaled in bearings in bearing housings 34 and 36. Said bearing housings 34 and 36, said packing gland assembly 42, and said second rotor or gear disposed in said housing 10 have not been shown in detail because these elements are conventional and their structure and operation will be clear to those skilled in the art. The various external elements of the pump such as housing 10, end plates 26 and 28, and cover plates 38 and 40 are held in assembled relationship by means of a suitable number of bolts as indicated. In the drawing only a few of said bolts have been shown so as to simplify said drawing.

Returning now to FIGURE 3, said chambers 16 and 18 are so positioned with respect to each other that if the diameters thereof were completed, said diameters would intersect. Thus, in one sense of the word, said chambers can be referred to as intersecting chambers. However, it is necessary that the wall of said chambers be interrupted and a portion thereof removed at and beyond the region of intersection, similarly as shown, so as to leave a space between said chambers and provide for communication with inlet port 12 and outlet port 14. The amount of said chamber walls which is removed depends upon size, configuration, and location of said inlet and outlet ports. The rotors or gears which are disposed in said chambers 16 and 18 mesh in the space between said chambers. Thus, said chambers 16 and 18, together with the space 20 therebetween, can be said to define or comprise the pumping cavity within said housing 10.

In the practice of the invention when it is desired to install a liner in a worn pump housing, such as housing 10 the chambers 16 and 18 therein are rebored to have a greater diameter and thus provide space for a liner element having a reasonable thickness. By way of example, a gear pump substantially like that illustrated in FIGURE 1 was relined. This pump, as manufactured, was provided with chambers 16 and 18 having a nominal diameter of 7 inches and a nominal length of 10 inches. The worn gear chambers 16 and 18 were rebored to each have a nominal diameter of 7.5 inches. Two liners, 22 and 24, having a nominal thickness of 0.25 inch, were formed from steel tubing. Said liners had a nominal length of 10.25 inches and when lightly pressed into said rebored chambers they extended beyond the ends of said chambers a distance of 0.125 inch. Recesses 30 and 32, having a shape like that of said liners 22 and 24 and having a width of 0.25 inch and a depth of 0.125 inch, were then milled into the inner surfaces of each of said end plates 26 and 28. Said end plates 26 and 28 were then mounted on housing 10 with the extended ends of said liners being received into said recesses 30 and 32. Upon completing assembly of the overhauled pump and placing same in service, it was found that said pump operated with a pumping efficiency essentially the same as a new pump.

From the above disclosure it is clear that the invention provides a means and a method for overhauling worn rotary pumps, such as gear pumps, and increasing the life of said pump as a whole. When the liners be come worn they can be replaced, thus extending the life of the pump as a whole indefinitely. At present, due to practices of pump manufacturers, this is the greatest ap-- plication of the invention. However, the invention is not thus limited. It is within the scope of theinvention to fabricate new pumps with removable liners in accordance with the invention. In such instances, when the liner becomes worn all that is necessary is to replace the worn liner with a new liner. I I

Also, while the invention has been described with particular reference to gear pumps provided with two gear chambers, the invention is not so limited.- The in= vention is applicable to other pumps, blowers, and like apparatus having only one chamber wherein a rotor e1e= ment rotates with peripheral contact or close clearance between same and the wall of the chamber.

While certain embodiments of the invention have been described for illustrative purposes, the invention obviously is not limited thereto. Various other modifi cations will be apparent to those skilled in the art in view of this disclosure. Such modifications are within the spirit and scope of the invention.

I claim:

1. A pump comprising: a housing having an inlet port and an outlet port; a chamber formed in said housing and comprising a pumping cavity communicating with said inlet port and said outlet port; a stationary liner of complementary shape mounted on the wall of said chamber, each end of said liner extending slightly be-' yond the respective ends of said chamber wall and said housing; a first and a second end plate, each substantial= ly closing one end of said housing; and a grooved recess of a shape like that of said liner formed in the inner wall of each of said end plates for receiving therein said extended ends of said liner when said end plates are mounted on said housing.

2. A pump comprising: a housing; first and-second spaced apart and aligned chambers formed in said housing and together with the space therebetween forming a pumping cavity; first and second end plates mounted on said housing and substantially closing the opposite ends of said cavity; and first and second liners having a shape complementary to and mounted on the wall of said first and second chambers, respectively, each end of each of said liners extending slightly beyond the adjacent respective end of said chamber walls and said housing and into first and second grooved recesses of like shape formed in the inner surface of each of said end plates.

3. In a pump comprising a housing, first and second spaced apart and aligned chambers formed in said housing and together with the space therebetween forming a pumping cavity, and first and second end plates sub stantially closing the ends of said cavity, the improvement comprising: first and second liners of complementary shape mounted on the wall of said first and second chambers, respectively, each end of each of said liners extending slightly beyond the respective ends of said chamber walls and said housing; and a firs-t and a second grooved recess formed in the inner surface of each of said end plates, said recesses having a shape like, and being positioned so as to receive therein, said extended ends of said liners.

4. A gear pump comprising: a housing having an inlet port and an outlet port; first and second intersecting chambers formed in said housing, said chambers being interrupted in the region of their intersection to provide a space therebetween; said chambers, together with said space threbetween, forming a pumping cavity communicating'with said inlet port and said outlet port; a liner of complementary shape mounted on the wall of each of said chambers, each end of said liner extending slightly beyond the respective adjacent end of said chamber walls and said housing; a first and a second end plate, each mounted on and substantially closing one end of said housing; and grooved recesses of a shape like that of said liners formed in the inner walls of said end plates for receiving therein said extending ends of said liners when said end plates are mounted on said housing.

5. A gear pump comprising: a housing having an inlet port and an outlet port; first and-second substantially circular spaced apart and aligned chambers formed in said housing and together with the space therebetween forming a pumping cavity communicating with said inlet port and said outlet port; a first arcuate liner mounted in said first chamber contiguous with the Wall thereof, each end of said first liner extending slightly beyond the adjacent respective end of said wall and said housing; a second arcuate liner mounted in said second chamber contiguous with the wall thereof, each end of said second liner extending slightly beyond the adjacent respective end of said wall and said housing; a first end plate and a second end plate, each mounted on and substantially closing one end of said housing; a first and a second arcuate grooved recess formed in the surface of each said end plate which faces said cavity, said first and second recesses having the same radius of curvature as said first and second liners respectively and being positioned in said surface so as to receive therein said extended ends of said first and second liners respectively when said end plates are mounted on said housing and thus prevent rotation of said liners; and first and second meshing gear means operatively disposed in said first and second chambers, respectively.

6. A method for overhauling and installing a liner in a gear pump comprising a first gear chamber formed in said housing, a second gear chamber formed in said housing in center point alignment with and spaced apart from said first chamber, said tWo chambers and the space therebetween defining a pumping cavity, and first and second end plates for mounting on opposite ends of said housing to substantially close said pumping cavity, said method comprising: reboring each of said chambers to a larger diameter; pressing into each said rebored chamber a liner having a shape complementary to the wall thereof, the ends of each of said liners extending slightly beyond the adjacent respective ends of said chambers; forming first and second grooved recesses in each of said end plates, said recesses having a shape like that of and being positioned for receiving therein said extended ends of said liners when said end plates are mounted on opposite ends of said housing; and mounting said end plates on opposite ends of said housing with said ends of said liners extending into said recesses.

References Cited by the Examiner UNITED STATES PATENTS 1,021,180 3/1912 Clifton 103-126 1,382,580 6/1921 Webb 103-426 2,324,903 7/ 1943 Beckman 103-126 3,155,311 11/1964 Jones 230- 3,155,313 11/1964 Bentele 230145 DONLEY J. STOCKING, Primary Examiner. WILBUR J. GOODLIN, Examiner. 

1. A PUMP COMPRISING: A HOUSING HAVING AN INLET PORT AND AN OUTLET PORT; A CHAMBER FORMED IN SAID HOUSING AND COMPRISING A PUMPING CAVITY COMMUNICATING WITH SAID INLET PORT AND SAID OUTLET PORT; A STATIONARY LINER OF COMPLEMENTARY SHAPE MOUNTED ON THE WALL OF SAID CHAMBER, EACH END OF SAID LINER EXTENDING SLIGHTLY BEYOND THE RESPECTIVE ENDS OF SAID CHAMBER WALL AND SAID HOUSING; A FIRST AND A SECOND END PLATE, EACH SUBSTANTIALLY CLOSING ONE END OF SAID HOUSING; AND A GROOVED RECESS OF A SHAPE LIKE THAT OF SAID LINER FORMED IN THE INNER WALL OF EACH OF SAID END PLATES FOR RECEIVING THEREIN SAID EXTENDED ENDS OF SAID LINER WHEN SAID END PLATES ARE MOUNTED ON SAID HOUSING. 